Competing WLANs

By Carmen Nobel  |  Posted 2004-11-08 Print this article Print

For the switches, the Gallaudet IT staff, together with Ease, installed Airespaces AireWave Director Software, which monitors RFs and adapts to changing WLAN conditions such as traffic and interference. The software automates tasks such as channel assignment, power control and load balancing.

The team also installed Airespace Control System software, which uses a GUI to illustrate parameters such as signal strength and VLAN (virtual LAN) assignments.

In addition, the team supplemented the Airespace gear with site survey and positioning software from Ekahau Inc.

"Its really slick," Batten-Mickens said. "You load it into the laptop and scan to see whats the best placement of the antenna."

The first challenge of installing the campus WLAN was controlling all the ad hoc WLANs that already existed, said Brooks. Rogue access points had beaten official campus access points to the punch.

"We presurveyed their campus and found about 20 different wireless networks," Brooks said. "Most of them were not secured or optimizing the channels."

Batten-Mickens was not surprised. Setting up an insecure WLAN is as easy as plugging something in, and most consumer-level access points will work even if the user does not implement security protocols.

Click here to read how Cisco Systems is improving WLAN security by adding support for Advanced Encryption Standard. "People could pop in a D-Link [Systems Inc.] or a Linksys access point anywhere," Batten-Mickens said. "It wasnt malicious; it was just a matter of ooh, a new wireless technology and ooh, lets give this a shot."

The university responded to the unofficial networks by publicizing the official network and offering free WLAN access across the board, concentrating on areas where ad hoc networks already existed.

"Where we found hardware already, they made sure we saturated that area as sort of an offering," Brooks said.

Now that the official WLAN is deployed, the Airespace software detects and blacklists rogue access points, but rogues are much less of an issue now that the university community knows about the official WLAN, Batten-Mickens said. Users log in to the system with an authorized ID. Generally, the WLAN supports both Windows- and Mac OS-based notebooks, but use of Wi-Fi-enabled handheld devices on the WLAN is also increasing.

As with many universities, Gallaudet is supporting all three IEEE WLAN protocols on its campus: 802.11b and 802.11g at 2.5GHz and 802.11a at 5GHz. Most of the traffic is on 802.11g.

Gallaudets plan for the 5GHz band is the only thing that distinguishes its WLAN as a network for a deaf clientele. 802.11a is gaining popularity in the industry as a potential protocol for voice traffic because it has more channels than the other protocols. Clearly, Gallaudet doesnt have a pressing need for VOIP (voice over IP). But the additional channels could be useful for multimedia applications when the 2.4GHz band gets crowded.

"There could be the need for [802.11a] in the future," Batten-Mickens said. "Were obviously video-intense here."

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